A surge in popularity for bodybuilding and forms of high-intensity interval training has led more young men to inject steroids, putting their fertility at risk, doctors say.
Anabolic steroids, testosterone and growth hormones ― some legal and others prohibited ― have become commonplace in the fitness market.
Supplements are easy to obtain, either online or direct from personal trainers.
Dr Fadi Baladi, an internal medicine specialist at Burjeel Day Surgery on Reem Island in Abu Dhabi, said the long-term effects of steroid use can be devastating.
“Steroid use is becoming very common, it is largely unregulated and there is no age limit, so they are starting at a very young age,” he said.
"The majority of my patients with related problems are aged 20-30 have been using these products from 18.
“There is a lot of peer pressure to look a certain way, and men want to bulk up quickly. It becomes contagious.
“They are usually getting supplied by their trainer, and come to me when they have problems starting a family.”
Both anabolic steroids and testosterone can harm fertility by interfering with hormone signals required for sperm production.
The extent of damage depends on the dosage, the kind of drugs taken and for how long they are taken.
Suddenly increasing levels of testosterone or growth hormone can often lead to baldness and increased body hair, while jaw size can also increase irreversibly.
Other symptoms include a surge in cholesterol, leading to heart problems, while the liver is subjected to high levels of chemicals and toxins, causing it to swell.
Medication can be prescribed to stimulate sperm growth, but effects are often irreversible.
Another problem is gynecomastia, or male breast growth.
When there is a sudden surge in testosterone, the excess is converted into the female hormone oestrogen, causing male breasts.
Normal male testosterone levels are about 15-17 nanomoles per litre, on average.
But the levels seen in bodybuilders seen by Dr Baladi after regularly injecting muscle-building testosterone have been high as 50 nmol.
“I see 10 bodybuilders in my clinic every day, it is running out of control,” Dr Baladi said.
“On a weekend, my waiting area is like a bodybuilders' showroom.
“When you take testosterone, the body thinks it no longer needs to produce it, so it shuts down, shrinking the testes.
“After three months, sperm count is usually zero.
“I see men with huge breasts, but all we can do is send them for breast reduction surgery.
“We have had 70 cases since the start of the year ― it is crazy.”
A 12-week course of human growth hormone typically costs about Dh1,000.
Steroids imported from Denmark, Brazil and China are most commonly used and vary in price.
A regular course of injectable drugs can cost up to Dh5,000.
Ross Gilmour, 35, a personal trainer and competitive bodybuilder from Scotland, said the fitness boom had led to more young people turning to drugs.
“I have been a fitness coach for 13 years, and I am seeing young people in their late teens and early twenties getting into anabolics ― that is not how it should work,” he said.
“It is not just in bodybuilding, other strength sports are seeing a lot of people use performance-enhancing drugs.
“Those taking them would probably deny it, but it is well known it is widespread, particularly in those without natural muscularity and strength to be competitive.”
Competitive fitness events ― a mix of strength, power and endurance workout ― exploded from around 2014 in the Middle East with competitions paying out hundreds of thousands of dollars in prize money.
It has led to more use of anabolics such as testosterone and growth hormone and other performance-enhancing drugs
A safer use framework that involves a medical check-up, regular blood tests and biomarkers to check the biological reaction is rarely followed, putting men at risk of developing serious health problems.
Mr Gilmore said people aged 18-24 should be looking at their diet, stress levels and how much they sleep before taking testosterone or any form of steroids.
"Most are going from zero to a hundred super quickly, with no preventative measures in place,” he said.
“That can lead to fast muscle growth, but there can be a lot of joint issues and injuries.
“Health should always be at the forefront of considerations, but that is rarely the case.”